The main objectives of this proposal are to produce Copenhagen line 2331 x Fischer 344, F1 hybrid male rats bearing R3327, a prostatic adenocarcinoma. The inoculated animals will be provided to investigators in the National Prostatic Cancer Project and other investigators working in the field. Extra material will be retained as a resource of frozen R3327 for in vitro studies. The plan is to maintain our production of F1 hybrids at 75 male rats/week. The rats will be inoculated with R3327 and used in research projects relating to human prostatic cancer. Additional tumor lines of R3327 (squamous cell carcinoma and non-hormone responsive adenocarcinoma) will be maintaned for comparative studies. A central repository will enable the National Prostatic Cancer Project to explore other models as they become available.